Mechanical positive driving system



Aug. 10, 1937. w. G. H. FINCH MECHANICAL POSITIVE DRIVING SYSTEMOriginal Filed Feb. 26, 1936 4 Sheets-Sheet 1 Snnentor WILLIAM 6H.F'INCH (Ittomeg Aug. 10, 1937. w. s. H. FlNCH v MECHANICAL POSITIVEDRIVING SYSTEM Aug. 10, 1937. w. H. FINCH MECHANICAL POSITIVE DRIVINGSYSTEM Original Filed Feb. 26, 1936 4 Sheets-Sheet 3 Fig25.

3nventor WILLIAM GH. FINCH 'Jttorneu Aug. 10, 1937. w. G. H. FINCH'MECHANICAL POSITIVE DRIVING SYSTEM Original Filed Feb. 26, 1936 4Sheets-Sheet 4 WILLIAM GHHNCH (Ittomeg Patented Aug. 10, 1937 UNITEDSTATES PATENT OFFICE Original applications February 26, 1936, Serial No.65,869, and April 6, 1936, Serial No. 72,991. Divided and thisapplication December 30, 1936,

Serial No. 118,191

6 Claims.

This invention relates to novel apparatus for substantiallyinstantaneously connecting and disconnecting a driven member from adriving member, together with novel means for compensating for inertialdisplacements due to the connections and disconnections.

This application is a division of the parent application Serial No.65,869, filed February 26, 1936, which matured into Patent No.2,047,863, entitled Telecommunications system, and is a division of mycopending application, Serial No. 72,991, filed April 6, 1936 andentitled Telepicture synchronizing system.

In the transmission of pictures to remote points, it is essential thatthe receiver picture drum be in phase synchronism with the transmitterdrum. Many attempts have been made to attain such phase synchronization.It is extremely desirable to provide a positive driving connectionbetween the motor and the revolving drum to avoid any deleteriouseiiects due to frictional coupling. In my Reissue Patent No. 19,575, Ihave disclosed a system for connecting and disconnecting the positivedriving connection between the driving motor and the drum in re sponseto synchronizing signals to maintain phase synchronization.

In my present invention, I utilize an overrunning or positive clutch formaintaining the drum in phase synchronism. To overcome the eiiects ofrotational inertia present in a large telepicture system having a largerevolving drum, I provide a flexible mechanical coupling between thepositive clutch and the receiving drum. This coupling is designed topermit a momentary phase displacement of the drum due to accelerating ordecelerating inertial forces acting on the drum during the substantiallyinstantaneous connection and disconnection thereof from the driv rigmotor. .The flexible coupling is further designed to promptlyautomatically compensate for these momentary phase displacements.

This compensation is accomplished by mechanical means of a positivenature, to bring the driven member or drum back to the position it hadat the instant of connection or disconnection. The flexible connectioncan accordingly be considered as a member in a mechanical positivedriving connection between the motor and the drum since no rubber, fluidor other relatively elastic connection is used. Elastic connections areundesirable for picture work since any tendency to set will distort thepicture reproduction.

It is accordingly an object of my present invention to provide a noveldriving system employing an over-running or positive clutch connectionto the driven member.

Another object of my invention is to provide a mechanical flexiblecoupling in the positive drive for a rotatable member, whichautomatically compensates for any momentary phase displacement due toacceleration or deceleration forces.

A further object of my invention is to provide a novel combination of apositive clutch engaging and disengaging means for a revolving memberand a positive driving connection to permit substantially instantaneousconnection and disconnection of the member.

Other objects of my invention together with the'foregoing will becomeapparent in the following description in connection with the drawings,in which:

Figure 1 is a plan view of a preferred embodiment of the telepicturereceiver.

Figure 2 is an enlarged cross-sectional view through the receiver drumand drive of Figure 1.

Figure 3 is a cross-sectional view taken through Figure 2 showing apartially enlarged plan view of the drive mechanism and clutch triplevers.

Figure 4 is a. perspective disassembled view of the clutch mechanism.

Figure 5 is a cross-sectional view illustrating a fragmentary detail ofthe internal clutch roller assembly.

Figures 6, 7 and 8 are cross-sectional views taken respectively along6-6, 'l--'I and 88 of Figure 2 showing details of the synchronizingclutch control mechanism.

Figure 9 is'a modification of the synchronizing clutch control mechanismcorresponding to Figure 7.

Figure 10 is a cross-sectional view along ll0 of Fig. 9.

Referring to Figure 1, the telepicture receiver is mounted on a castiron base I I if it is designed for non-portable use. Synchronous motorI2 drives the receiver drum l3 through the overrunning clutch H andsuitable gearing contained in housing I 5. Synchronous motor I! isconnected by leads l6 to electrical supply lines I! for electricalenergization thereof. Reduction gearing l8 connects worm or feed screw Ito spindle end 20 rotating with drum l3. If drum l3 rotates 100revolutions per minute and 100 scanning lines per inch are used, thepitch oi. worm'lfl and its rate of revolution will be designed toadvance receiver carriage 2| at the rate of one inch per minute so thatthe scanning of the film 22 mounted on drum l3 will progress in acontinuous helical path. The light beam 23 emanating from focusingsystem 24 in this example is designed to be .01 of an inch in width toprevent translation overlapping. Carriage 2| houses the receiverelectro-optical system and rides on V-tracks 25 and 25 with V-rollers 21and 23.

The record sheet 22 is clamped upon drum |3 by clamping members 30. Ascale is marked upon the drum in the under-lap portion to indicate thelength of the record sheet being used. The plurality of roller sections3| are shown out of position and are used to aid in smoothly mountingrecord sheet 22 on drum |3 in a manner described in the parentapplication already referred to. Drum i3 is rotatably supported bypointed spindle 32 supported in tail stock 33.

Figure 2 is the cross-sectional view of Figure 1 through the axis ofdrum l3, illustrating in detail the mechanism for driving and mountingdrum i3. The shaft 34 driven by the motor |2 through the flexiblecoupling 35 rotates worm 35 which drives worm gear 31. The hub 33 ofworm gear 31 is connected to the clutch driver 43 by projections 4| ofthe hub 35 into corresponding grooves in the clutch driver 45. The wormgear 31 and the clutch driver 40 are free to rotate upon the spindle 42.The housing l5 encloses the worm and pinion drive and contains bearing43 which supports one end of the spindle 42. The opposite-end 44 ofspindle 42 is conical and coacts with the metallic insert 45 pinned toend plate 45 of drum |3 by pin 41, and supports drum l3. Metallic insert41 attached to opposite end plate 48 coacts with the conical end 43 ofthespindle 32 supported in tail stock 33. Hollow shaft 50 rigidlyconnects the metallic inserts 45 and 41. Drum i3 is accordinglyrotatably supported by the conical ends 44 and49. I

Figure 4 is a perspective illustration of the overrunning clutch l4disassembled to more clearly explain its operation. The clutch cam plate5| is rotatably mounted within the clutch driver 45 upon spindle 42(shown in dotted). There are four openings 52 on the surface of the camplate which contain metal cylindrical rollers 53. The clutch stop plate54 is fitted adjacent to the cam plate 5| and contains four pins 55which coact with the cylindrical rollers 53.

Figure 6 is a sectional view through the overrunning clutch l4 takenalong 5-5 of Figure 2 illustrating the character of the recesses 52 inthe cam plate 5|. The principle of the overrunning clutch is well knownin the art. The rollers 53 are wedged between the inner surface 55 ofthe clutchdriver 43 and the inclined surfaces 51 of the recesses 52.Plungers 58 set in cam plate 5| are forced against each roller 53 bysprings 53 set within the cam plate 5|. The wedging action of therollers 53 between surface 55 and inclined surfaces 51 serves as apositive connection between the clutch driver 40 and the cam plate orclutch driven member 5|.

Figure 5 is a cross-sectional enlarged detailedview illustrating thearrangement of a roller 53 and its stop plate pin 55 within a recess 52of the cam plate 5| in engaged position where the plunger 53 is pressedagainst the roller 53 by spring 53 set in the cam plate 5|.

Referring to Figures 2 and 4, the hub 50 of cam plate 5| has a V notch5| atone end thereof which coacts with a V projection 52 on thecoupling. member 53. Coupling member 53 has keyway's'54 that slidablyengage corresponding keys 55 set in the spindle 42. It is to beunderstood that the coupling member 53 is slidable axially on thespindle 42 and that this coupling member 53 provides the drivingconnection for the spindle 42 since no relative angular'movementtherebetween is possible.

Accordingly, when the overrunning clutch I4 is engaged the motor driveI2 is transmitted by the worm and pinion 35-31, the engaged clutch i4and the coupling member 53 to the spindle 42. The face plate driver 55is rigidly mounted on the spindle 42 by pin 51. A projection or key 58,on the face 59 of the face plate driver 55, sets into a correspondinggroove in the end plate 48 of the receiver drum I3. A positive drivingconnection is accordingly had between the motor l2 and the receiver druml3 when the positive or overrunning clutch I4 is engaged.

A set of pins 10 project from the opposite end II of the face platedriver 55 to press the coupling member 53 into engagement with the Vnotches 5| of the cam plate 5|. Springs 12 press the pins 10 against theface 13 of the coupling member 53. A positive driving connection ofcoupling member 53 with cam plate hub 50 is had for all practicalpurposes in the operation of the system, since the pins I3 maintain theengagement of V projection 52 and V grooves 5| during the driving cycleof the drum.

An important feature of my present invention resides in the automaticconnection and disconnection of the positive or overrunning clutch M tomaintain the revolving receiver drum l3 in phase synchronism with thetransmitter drum (not shown). In my Re. Patent No. 19,575, is describedone method for connecting and disconnecting the positive drive frombetween the source of motive power and the revolving drum.

My present invention embodies the principle of the overrunning clutch inan instantaneous synchronization' mechanism. Synchronization accordingto Re. Patent No. 19,575 depends upon the actuation of a pawl engaging aratchet wheel in the positive driving connection. The limits of phasingpositions are accordingly within the pitch or width of one tooth of theratchet wheel.

By employing an overrunning clutch, the positive drive is had during therotation of the drum l3 and accurate phase synchronization is feasibleat any point in the circumferential movement of the drum. The stop plate54 contains the pins 55 which coact with the wedging rollers 53. Whenthe cam plate 5| is driven by the clutch driver 45 during the wedgingaction ofthe rollers 53, the stop plate 54 is also driven and revolveswith the cam plate 5|. However, I provide a notch I4 on the periphery ofthe stop plate 54 biased by spring 11 toward the stop plate 54.

Figure 7 illustrates the engagement of lever.

projection 15 with the corresponding notch 14 in the stop plate 54. Inthis position the stop plate is prevented from further rotatingcounterclockwise, as indicated by the arrow. The pins 55 accordinglyabut the rollers 53 within the overrunning clutch .l4 and force therollers 53 against the piungers 58 to disengage the clutch l4, as willbe understood by those skilled in the art. The rollers 53 are movedalong the inclined surfaces 51 releasing the wedging action of therollers 53 from between the cam plate 5| and the inner clutch driversurface 55. The motor l2 continues to rotate the clutch driver 40 butthe driving of the drum I8 therefrom is instantaneously discontinued.

A pawl 88 is mechanically biased toward the stop plate 84 by spring 8i.Pawl 88 projects into a notch 82 on the periphery of stop plate 88 atthe instant the projection I8 of the trigger lever I6 engages the notchI8 in the stop plate 88 The pawl 80 accordingly prevents rebound o? thestop plate when its notch is arrested, thus insuring a positivedisengagement oi the overrunning clutch I4.

Figures 3, 7 and 8 illustrate one modification for actuating the clutchI8 in response to synchronizing signals. For rapid engagement of theoverrunning clutch II in response to synchronizing signals,'i'allingweight 88 is caused to impact theend 88 of the trigger lever I8,removing the projection I5 from the notch I8 in the stop plate 84 andpermitting the plungers 88 to wedge the rollers 53 between the cam plateII and the clutch driver 88. The movement of weight 88 is guided by post85 through a hole inthe center of the weight 88.

Figure 7 illustrates the weight in its upper position. A projection 88on the armature 81 of the synchronizing magnet 88 holds the weight 83 inits upper position in readiness for release. When a synchronizingimpulse is impressed upon magnet 88 through its leads 8888 in a mannerwell known in the art and described in detail in the parent application,the armature is attracted toward the magnet 88 against the spring 8|permitting the weight 83 to drop and impact the end 88 of trigger leverI6 to drivingly engage the clutch I 8 as illustrated in Figure 8.

The weight 83 is replaced to its upp r position by means of the lever82. A pin 88 projects from the surface of the stop plate 88 and once perrevolution of the stop plate, the pin 88 presses the end 83 of lever 82downward so that the opposite end 85 automatically raises the weight 88to its upper position shown in dotted in Figure 8. Spring 8I moves thearmature 81 away from the magnet 88 permitting the projection 88 toengage the bottom corner of the weight 83 to hold it in its upperposition in readiness for its cyclical release. Figure 3 is a sectionalview through Figure 2 showing the driving connections from the motorcoupling 88 and is a plan view of the synchronizing levers I6 and 82,weight 83 and magnet 88.

The receiver drum I3 is maintained in phase synchronism by means ofcyclically transmitted synchronizing signals during the underlap periodof the transmitter drum (not shown). The receiver synchronizing cam I88is mounted at the end 28 01 the spindle 82 outside the housing I8clearly illustrated in Figure 2. The subtended angle oi! the cam nib I8Imay be made equal to the corresponding subtended angle of the underlapportion of the receiver drum I8 so that the receiver synchronizingswitch I82 will be maintained open during this interval to causesynchronizing magnet 88 to be connected in .the circuit of the receiveramplifier output as .described in the parent application.

As there described, the amplifier is a class B amplifier and the tubesare biased to cut oil", so that when no signal is impressed in the inputcircuit, zero plate current will flow and the synchronizing magnet 88connected therein will not be energized until the synchronizing impulseis impressed. In my preferred embodiment. the synchronizing impulse isor a magnitude greater than the largest telepicture signal so that thesynchronizing magnet will respond only to the synchronizing signals.

ably made of aluminum to reduce its rotational inertia, The couplingmember 88 coacting with v the driven, cam plate ii of the overrimningclutch I8 acts as a shock absorber to resist the inertial resistance ofthe drum I8 during its starting from rest to synchronous speed, or ofany inertial forces it may present during the synchronizing action.

When there is a tendency for the cam plate 8| to advance in phase withrespect to the coupling member 88, the coupling member will'slideaxially along the spindle 82 away from the clutch cam II and against thepressure of the pins I8 mechanically biased by springs I2. The V notches8| 0! the cam hub 88, coacting with the V projections 82 of the couplingmember '88, eiiects a positive driving action between the two when theyare in engagement. A relative motion between the cam plate II and member.88 causes its V projection to slide away from the V notches 8Iproportional to the iorces tending to resist their in-phase movement.Such forces occur momentarily, and the coupling member 88 is againforced into normal engagement with thevnotchesflbythepinsll.

Any momentary relative movement between the clutch driven member 8I andthe member 88' is automatically compensated by the return of the Vprojections 82 into normal engagement with the V notches N. A spring I88connects an elet pin I88 secured in the coupling memher 8 and anothereyelet pin: I8.|' secin'edin the hub 88 of the cam plate 8|, asillustrated in Figures 7 and 8. Spring I88 facilitates the automaticreturn engagement oi. the V projection" 82 lithe Vnotches 8I ot'thecorresponding memor splined to the spindle 82 and the face plate driver88 is rigidly keyed to the spindle 82, the

,. receiver drum I8 is driven positively from the coupling member 88.,The source of motive- Since, the coupling member a is mam, keyedconnection. The relation of the hub 88 and coupling member 88as alreadydescribed is a flexible positive connection since it permits momentarychanges in phase, but-automatically returns to the normal phaserelation. .The synchronizing apparatus operating on the clutch stopplate 88 disconnects the positive driving connection between thesourceoi motive power I2 and the receiving drum I8 at the positive oroverrunning clutch I8 it the receiver drum I8 is not in phasesynchronism with the transmitter driun (not shown).

Itistobeunderstoodthatthereceiverdrum I8rotatesinandinphasewiththecorresponding transmitter drum. and that the carriage 2I simultaneouslyadvances the impinging signal light beam 28 axially along the him 22mounted on the drum I8 to record the picture being transmitted, Theintensity of the light beam 23 sharply focused upon the film 22 variesin accordance with the shading of the picture being transmitted as isevident to those skilled in the art.

A modification of the synchronizing magnetclutch trigger arrangement isillustrated in Figure 9 corresponding to Fig. 7. The synchronizingmagnet H corresponding to magnet 88 is mounted on a bracket III belowthe surface H2 of the base II. The poles H3 of the synchronizing magnetIIll project through the surface H2 to coact with the armature plate II4attached to the end H5 of the trigger lever I6.

Figure is a cross-sectional view through the magnet III] illustratinghow the armature plate I I4 is arranged above the two poles I I3--I I3of the electromagnet III) and how the trigger end H5 is positionedbetween the poles II3-I I3. The trigger I6 is accordingly directlyactuated by the synchronizing magnet H0 without the use of a fallingweight 83 as in the hereinabove described modification. While the clutchI4 and stop-plate 54 are rotating, the lever I6 will be held in thedotted position of Fig. 9 so that the armature plate H4 will be close tothe poles I I3 of the magnet I Ill. The peripheral surface of thestop-plate 54 will abut the trigger projection I5 and press the lever I6.toward the poles H3 against the action of the biasing spring 11. Thearmature plate I I4 will accordingly be close to the poles H3 of themagnet H0 during the major portion of the revolution of the stop-plate54, but will tend to be moved away under the'action of spring 'II whenthe notch I4 comes in engaging position with the projection I5 of thetrigger I6.

If the drum I3 is in phase synchronism, the synchronizing impulses willarrive at the synchronizing magnet III through leads II6-IiI'I in timeto hold the trigger 16 away from engagement with the stop-plate notch I4and permit the drum I3 to continue in phase synchronism. It is to beunderstood that if the drum I3 is out of phase synchronism, the notch I4will engage the trigger projection I5 to disengage the positive oroverrunning clutch I4. When the synchronizing signal is received by themagnet I III, the stopplate 54 is released and the clutch reengages torotate the drum in proper phase synchronism.

I claim:

1. The combination with a driving means and a driven shaft, of apositive clutch for connecting and disconnecting said driving means andshaft comprising a driving member connected to said I driving means anda driven member; an element for coupling said driven member to saiddriven shaft, slidably keyed to the driven shaft, and having a contactengagement with said driven clutch member symmetrical about said drivenshaft for balancing the forces of coupling, and means for maintainingsaid element in continuous engagement with said driven clutch memberincluding structure coaxial with and secured to the driven shaft, havingpins spring biased against said coupling element, for permitting amomentary relative angular displacement between said driving means andshaft.

2. The combination with a driving means and a driven shaft, of apositive clutch for connecting and disconnecting said driving means andshaft comprising a driving member connected to said driving means and adriven, member; an element for coupling said driven member to saiddriven shaft, slidably keyed to the driven shaft, and having a contactengagement with said driven clutch member symmetricaLabout said drivenshaft for balancing the forces of coupling, said engagement comprisingV-projections from said element cooperative with V-notches in saiddriven member arranged on opposite sides of the driven shaft and meansfor maintaining said element in continuous engagement with said drivenclutch member including structure coaxial with and secured to the drivenshaft, having pins spring biased against said coupling element, forpermitting a momentary relative angular displacement between saiddriving means and shaft.

3. The combination with a driving means and a driven shaft connected torotate a drum, of a positive clutch for connecting and disconnectingsaid driving means and shaft comprising a driving member connected tosaid driving means and a driven member; an element for coupling saiddriven member to said driven shaft, slidably keyed to the driven shaft,and having a contact engagement with said driven clutch membersymmetrical about said driven shaft for balancing the forces ofcoupling, said engagement comprising V-projections cooperative withV-notches arranged on opposite sides of the driven shaft and means formaintaining said element in continuous engagement with said drivenclutch member for permitting a momentary relative angular displacementbetween said driving means and shaft; means for arresting the rotationof said driven clutch member at a predetermined angular position wherebysaid drum will be returned to said predetermined angular position afterthe momentary angular displacement resulting from inertial forcesthereof.

4. The combination with a driving means and a driven shaft connected torotate a drum, of a positive clutch for connecting and disconnectingsaid driving means and shaft comprising a driving member connected tosaid driving means and a driven member; an element for coupling saiddriven member to said driven shaft having a contact engagement with saiddriven clutch member symmetrical about said driven shaft for balancingthe forces of coupling and permitting a momentary relative angulardisplacement between said driving means and shaft; and means forarresting the rotation of and preventing rebound of said driven clutchmember at a predetermined angular position whereby said drum will bereturned to said predetermined angular position after the momentaryangular displacement resulting from inertial forces thereof.

5. The combination with a driving means and a driven shaft connected torotate a drum, of a positive clutch for connecting and disconnectingsaid driving means and shaft comprising a driving member connected tosaid driving means and a driven member; an element for coupling saiddriven member to said driven shaft, slidably keyed to the driven shaft,and having a contact engagement with said driven clutch membersymmetrical about said driven shaft for balancing the forces ofcoupling;-means for maintaining said element in continuous engagementwith said driven clutch member including structure coaxial with andsecured to the driven shaft, having pins spring biased against saidcoupling element, for permitting a momentary relative angulardisplacement between said driving means and shaft; and means forarresting the rotation of and preventing rebound of said driven clutchmember .at a predetermined angular position whereby said 6. Thecombination with a driving means and a driven shaft connected to rotatea drum, of a positive clutch for connecting and disconnecting saiddriving means and shaft comprising a driv- 5 ing member connected tosaid driving means and a driven member; an element for coupling saiddriven member to said driven shaft, slidably keyed to the driven shaft,and having acontact engagement with said driven clutch member symmetri-10 cal about said driven shaft for balancing the forces of coupling,said engagement comprising V-projections from said element cooperativewith V-notches in said driven member arranged on opposite sides of thedriven shaft; means for 15 maintaining said element in continuousengagement with said driven clutch member including structure coaxialwith and secured to the driven shaft, having pins spring biased againstsaid coupling element, for permitting a momentary relative angulardisplacement between said means; and means for arresting the rotation ofand preventing rebound of said driven clutch member at a predeterminedangular position whereby said drum will be returned to saidpredetermined angular position after the momentary angular displacementresulting from inertial forces thereof, comprising a stop plate coactingwith said driven clutch member having a notch in its periphery and apawl spring biased against the periphery of said stop plate for engagingsaid notch.

WILLIAM G. H. FINCH.

